Catechism of the Catholic Church

The Letter to the Hebrews, in its great eulogy of the faith of Israel's ancestors, lays special emphasis on Abraham's faith: "By faith, Abraham obeyed when he was called to go out to a place which he was to receive as an inheritance; and he went out, not knowing where he was to go." By faith, he lived as a stranger and pilgrim in the promised land. By faith, Sarah was given to conceive the son of the promise. And by faith Abraham offered his only son in sacrifice. (59, 2570, 489)